Japanese Patent Laying-Open No. 2009-292362 (PTL 1) discloses a technology by which, in a vehicle including an engine and a motor coupled to an output shaft of the engine via a planetary gear mechanism, upon determination of whether or not a misfire at each cylinder of the engine is present based on rotational fluctuations of the engine, a threshold value used for the misfire determination is changed depending on whether or not torque for the prevention of an abnormal sound generated at the planetary gear mechanism is being output from the motor.